Liquid-fuel burner



G. U. MORGAN LIQUID FUEL BURNER Filed May 5, 1923 2 Sheets-Sheet 1 INVENTOR July 8. 24! z G. u. MORGAN LIQUID FUEL auausa Filed May E). 1923 2 Sheets-Sheet. 2

INVENTOR:

Patented July 8, 1924.

U IT D STATES GEORGE URQUHAR-T MORGAN, OF LONDON, ENGLAND.

LIQUID-FUEL BURNER.

Application filed May 5,

To all whom it may concern:

Be it known that I, GEORGE URQUHART 'MoReAN, a British subject, and resident of 20 Bennett Street, Stamford Street, London,

S. E. 1,, England, have invented certain new and useful Improvements in Liquid-Fuel Burners (for which I have filed an application in England dated 2nd June, 1922), of whichthe following is a specification.

' This invention relates to burners for operating with liquid fuels such, for example, as that set forth in the specification of British Patent No. 175785, dated 1st December, 1920. It is the main object of the present invention to enable a burner of such general type to be used either with oil fuel fed under pressure alone, or with oil fuel fed under pressure, as well as a small supply of steam or air for scavenging the burner and improving its efliciency, or with asupply of oil under gravity or other light pressure ,head together, with atomizing either by means of steam or compressed air. The types of burners mostlargely used hitherto have usually been adapted for working under one or two of these methods and if it is necessary to change over the operation from this one or these two methods to yet another method, it has usually been neces- 3 0 sary to change the burner. The present invention further aims at providing an accurately. controlled feed of oil fuel adapted to cause the oil to issue in a finely divided condition which facilitatesits atomization. The burner set forth in the specification of British Patent 175785 was provided with a needle capable of being drawn back behind the orificeof the burner when it was desired to allow of a rapid flow of oil, or capable of being adjusted until a portion of the needle fitted closely in the orifice when the feed of oil was to be cut off, while finally the needle was capable ofbeing moved for- ,wardly in order to allow of a smaller control feed of oil from the part of the needle to the rear of the cut-off portion.

The improved burner ispreferably made to operate in the same general manner, but according to the present invention the needle is formed as a cylinder with axially di rected :flutes or spiral groovescut therein leading up to a cylindrical surface which .fits ina cylindrical part of the burner. orifice in one position of adjustment to cut off ,the flow of' fuel. This construction, when after set forth.

19 23 Serial No. 636,937.

the needle is adjusted to the forward position, serves to guide the needle centrally owing to the fluted or grooved .part engaging the cylindrical part of the burner orifice and it also distributes the flow of'oil evenly upon the needle when in this forward position.

The depth of the flutes or spiral grooves is reduced towards the cylindrical surface which may be termed the cut-off ring, while, if desired, the Width of the flutes or grooves may increase as the depth increases to allow the fuel to expand laterally. In addition to the advantages already mentioned, the use of the flutes or grooves cut in the needle improves the accuracy of adjustment owing to the shape of the said flutes or grooves.

The spiral grooves are preferred because of the tangential or rotary movement which they. impart to the stream of oil, but, with either construction, the oil is discharged over the annular cut-off surface in the form of a thin sheet which is easily atomized for burningpurposes. j The invention also provides-improved means for controlling the admission of air to the burner and generally improving the construction thereof as herein- One form of fuel burner constructed in l accordance with the present invention is illustrated by way of example in the accompanying drawings, in which- Figure 1 is an elevation of the burner showing its supply pipes;

Figure 2 is a;central vertical section of the burner; I

Figure 3 is a vertical cross section on the line III-Ilfof Figure '1;

Figurel is an end view of the burner;

Figure 5 is an enlarged section of the nozzle portion of the burnerflshowing the formation of the needle; and

V Figure is an enlarged vertical section of the needle. i v

' The general features of the burner illustrated are similar to those set forth inthe specification of British Patent No. 175785. The body portion 1 is a double walled structure, the inner. tubular part2 being formed The tubular wall 2 of the body 1 forms the fuel chamber of theburner while the outer cylinder 7 of the body 1 encloses the chamber 8 for the atomizing agent, which is generally either steam or compressed air and an adjustable cap 9 is screwed upon this chamber at the front. The cap 9 isformed as a nozzle surrounding the nozzle 3 of the oil chamber and the shapeof the internal surface of the nozzle 9 and the external sun face of the nozzle 3 are such as shown in Figure that the stream of air. or steam used for atomizing purposes issuing between .2 the parts 3 and dis directed inwardly at the form of flexible pipes 12, 13, while a fuel valve is shown at 14 and a valve for the compressed alror steam at 15, while a bye-pass valveis shown at 16 enablingthe compressed v atomized for burning air or steam to flow tothe socket 10 at intervals whendesired and thence to the fuel chamber to blow through this chamber and the nozzle? 1 The needle 6 is formed as a cylinder on which spiral grooves 17 are cut leading up to a short cylindrical surface 18 which in one position of adjustment fits within the short cylindrical borel9 in the burner orifice and completely closes the nozzle 3; 'Instead of spiral grooves 17, this portion of the needle may be formed with longitudinal flutes, but, as already mentioned, the spiral grooves are preferred because of the tangential or rotatory movement which they impart to the 'outfiowing stream of oil, but in either case the action is substantially the same to the extent that theoil as it is discharged over the annular cut-off surface 18, is'distributed in the form of athinsheet' which iseasily urposes. The depth of the spiral grooves 1 or flutes is reduced towards the cut-ofif surface 18 andalthough as shown the grooves 17 remain of constant width, the width of the walls between the groovesmay be reduced towards the front end so that the oil passing along the flutes or grooves can expand laterally.

T One great advantage of forming the needle nthe'way particularly shown In Figure 5, is

that there extend backwardly from the annular cut-offsurfatce 18 spiral ribs of the same diameter as itss'urface, whichserveto keep'the' needle 6 central as it is moved forwardly through the aperture at 19, thus avoiding any'risk of unequal distribution of the oil due to lateral deflection of the needle The purpose of such grooves, if provided, 7

would be mainly to impart a rotating movement to the out-flowing oil when the needle is used in the retracted position, such as shown in Figure 5 for the purpose of permitting a very large flow of oil to take place 1n a given period. In order to guide the needle 6 in the burner passage, the needle is shown provided with longitudinal ribs 21 which are illustrated as straight, but may be spiral shaped if desired. They guide the needle in the fuel chamber and will allow the oil fuel to flow along the needle between them. As seen in Figure 2, the part of the needle 6 to the rear of the point at which the oil enters through the socket 10 is of plain cylindrical shape working in the gland 5. The needle is adjusted by means ofa milled head 22 fixed to a flange 23. This flange has a part rolled into a groove 24 in the rear part of the needle, so that the needle is constrained to advance andretire with the i 100 flange 23, but is freenot to rotate with it. The flange 28 upon rotation of the milled head 22 screws upon therear extension 4:

of the body of the burner and advances orretracts the needle as desired. The fiange23 will usually have graduations for reading against a mark on the stationary part 4t of the burner. In order to enable the stu'fling box 1, 5, to be tightened up without removing the flange 23, the latter is slotted asseen at 25 in Figure 1 to enable a spanner to be inserted to engage the hexagonal end 26 of the gland 5. V

In order to adjust the opening between the nozzle member9 and the nozzle- 3'and face of the member 9 and the corresponding face on the body 1. These are'not illustrated in the drawing as in Figure2 the nozzle 9 is shown in its extreme position with the openingclosed. It isnot usually 1 necessary to adjust the opening between the nozzle 9 and the nozzle 3 through which the steam or air for atomizing passesvery frequently and by the use of washers the adjustment can be made accurately while maintaining a tight joint which prevents leakage of steam or air undcrpressure between the member 9 and the body portion l. A cap member 27 is shown screwed on to the outersurface of the nozzle 9. The member 27 is again adjustable and'has around its periphery slots 28 which serve for the admission of primary induced air. The member 27 is again shown in Figure 2 in its extreme. position with the opening between it and the nozzle 9 closed. -This member also can be adjusted to give the correct opening for the particular purpose by means .of *washers inserted between it and the nozzle 9.

The burner so far described is slidably supported in a cradle 29 formed with'lateral lugs 30, 31, by means of which the whole burner is supported. This cradle 29 has a rearward slotted extension 32 intowhich the burner can slide from the rear. The exact position in which the burner is secured is adjustable for a purpose which will be explained below. IVhen the burner has reached the, desired position it is secured by a stud 33 engaging the slot in the extension 32 and screwed into an aperture in the body part 1. The forward part of the cradle 29 is broadened laterally and proj ects through the front plate of the boiler in which it makes a good fitand in which it is secured by bolts passing through the lugs 30, 31. The central cylindrical part 29 acts as a combustor and is provided with a renewable liner 29 shown in Figure 2 but not in Figure 4:.

In order to introduce auxiliary air, a ring 34. is provided fitting between two flanged members 35, 36, each of which is milled externally and the ring 34 is furnished with a port 34?. The auxiliary air may be supplied under pressure if necessary, for example, when the burner is applied to a forced draught furnace, in which case an air inlet pipe is attached to the ring 34. The flange 35 by means of axially directed slots 37 (see Figure 4L) controls the inlets for air to the spaces 40 around the combustor 29 and this air serves to cool and prolong the life of the combustor 29 and mixes with the oil and air mixture when the latter has left the mouth of the combustor. The flange 36 by rotating an apertured ring 38 controls slots 39 in the cradle 29 and thus controls the admission of air through the slots 39. By adjusting the burner forwardly or rearwardly in the cradle 29, as already mentioned, the proportion of this air passing through the slots 39 which enters the combustor 29 in front of the member 27 or which passes through the slots '28, can be controlled. The admission of air in this way reduces the roaring noise which the burner is otherwise liable to make in operation.

When a pressure feed of oil is used it is necessaryto preheat the oil. Any convenientmeans for this purpose may be used and in some cases, for instance, the heat develop'ed in an air compressor for supplying air under pressure to force the oil from a tankmay be utilized to pre-heat the oil which flows as a cooling medium around the compressor cylinders. 7 Additional heat is supplied by steam, for example, where available or by passing the oil through coils heated by gas flames and so forth as may be required 1 Having thus described my invention what I claim as new and desire to secure by Letters Patent is 1. In a burner for liquid fuel, the combination of a body portion formed with a central nozzle aperture and with concentric chambers for the fuel and for an atomizing agent and an atomizing needle carried-ma longitudinally adjustable manner in said body and formed with a cylindrical surface co-acting with a cylindrical part of thenozzle aperture and with axially directed grooves disposed to the rear of the cylindrical surface and'leading up to the latter.

2. In a burner for liquid fuel, the combination of a body portion formed with a central nozzle aperture and with concentric chambers for the fuel and;for an atomizing agent and an atomizing needle carried in a longitudinally adjustable manner in said body and formed with a cylindrical surface co-acting wit-ha cylindrical part of the nozzle aperture and with axially directed spiral grooves disposed to the rear of the cylindrical surface and leading up to the latter.

3. In a burner for liquid fuel,'the combination of a body portion formed with a central nozzle aperture and with concentric chambers for the fuel and for an atomizing agent and an atomizing needle carried in a longitudinally adjustable manner in said body and formed with a cylindrical surface co-acting with a cylindrical part of the nozzle aperture and with axially directed spiral grooves disposed to the rear of the cylindrical surface and leading up to the latter, the depth of said grooves decreasing towards the cylindrical surface.

4:. In a burner for liquid fuel, the combination of a body portion formed with a central nozzle aperture and with concentric chambers for the fuel and for an atomizing agent andan atomizing needle carried in a longitudinally adjustable manner in said body and formed with a cylindrical surface co-acting with a cylindrical part of the nozzle aperture and with axially directed grooves disposed to the rear of the cylindrical surface and leading up to the latter, said needle also being formed with longitudinal ribs to the rear of said grooves for guiding the needle in the burner passage.

5. In a burner. for liquid fuel, the comtubular fuel chambera'nd a chamber concentric therewith for the atomizing agent, a stuffing box secured in the rear end of said body portion, an atomizing needle lodged within and guided in saidfuel chamber and formed with axially directed grooves and passing through said stufiing box and a milled flange screwedupon the rear portion of said body and secured tothe rear end of the needle and slotted to allow the insertion of a tool to adjust the gland of said stufiing box without removal of said milled flange.

v6. In combination, a cradle having cylindrical walls formed with air inlet ports and a burner for liquid fuel longitudinally adjustable therein, comprising a body portion formed with a front nozzle and with concentric chambers for fuel and for an atomizi-ng agent, an atomizing needle carried therein in a: longitudinally adjustable manner, an annular member carried on theforward end of said body portion and adjustable axially thereof to control the flow ofan atomizing agent around said nozzle, asecond member carried by saidfirst member and adjustable .axiallythereon leaving a chamber for additional air between said second and first named members, the adjustment of said second named member regulating the flow of additional air radially inwards through the 7 air inlet ports in said cradle through said chamber. I

7. In combination, a supporting cradle having walls formed with air inlet ports, a burner for liquid fuel carried therein in a longitudinally adjustable manner, a cylindrical ring surrounding the ports of said cradle'forming an air chamber between said ring and said cradle, a slotted flat ring mounted upon the front of said cylindrical ring and having slots co-acting with axially directed air passages in said cradle and a controlling member comprising a slotted cylindrical portion rotatably mounted on said cradle and co-acting with the ports therein and a flat annular portion closing the rear end of the air chamber.

8. In combination, a supporting cradle comprising a cylindrical central member with outer axially directed passages forming a combustor, said cylindrical portion having peripheral air inlet ports towards its rear end, a burner for liquid fuel secured in a longitudinally adjustable manner in said cradle, a member rotating on the outside of said cradle with axially directed ports controlling the passage of air to spaces around said combustor and a second member rotatable 011 the outside of said cradle with radial directed ports co-acting with the ports in the periphery of said cradle for controlling the supply of additional air to said liquid fuel burner.

In, witness whereof, I hereunto subscribe my name this 23rd day of April, 1923.

GEO. URQUHART MORGAN. 

